Overwind device



y 1962 A. o. WOLLENTIN 3,044,529

OVERWIND DEVICE Filed Jan. 14, 1959 2 Sheets-Sheet i FIG. 5. FIG. 7.

58 so 40 5e 60 40 IN V EN TOR.

y 1962 A. o. WOLLENTIN 3,044,529

OVERWIND DEVICE Filed Jan. 14, 1959 2 Sheets-Sheet 2 Fl. FIG.2. G

BYW

United States Patent Ofilice 3,644,529 Patented July 17, 1962 3,044,529OVERWIND DEVICE Alvin O. Woilentin, Bloomfield, N.J., assignor toWestinghouse Electric Corporation, East Pittsburgh, Pa., a corporationof Pennsylvania Filed Jan. 14, 1959, Ser. No. 786,824 5 Claims. (Cl.153-67) The present invention relates to coil-winding machines and, moreparticularly, to an improved overwind device for such machines.

In the manufacture of coiled filaments for incandescent lamps and thelike it is necessary (in order to accurately mount the filament onthelamp stem) that the straight uncoiled end-leg portions extend fromthe coil or body portion of the filament with the same predeterminedangularity and in the same plane.

I Heretofore it has been known to wind coiled filaments on an automaticcoil-Winding machine of the type shown in US. Patent No. 2,179,296,issued November 7, 1939, to F. B. Iden. In a coil-winding machine ofthis type the end of uncoiled wire is fed from a reel through a pair ofjaws and a coiling die, parallel to a retractable mandrel, and the endis clamped by a wire-gripping finger on the nose of the rotatablecoiling head to form the first straight uncoiled end-leg portionparallel to the longitudinal axis of the body. The reel, coil-guide headand coiling die are mounted on a wire-feed-gripper slide movablelongitudinally with respect to the axis of the mandrel, which isretractable into and rotatable with the coiling head. The wire-grippingfinger holding the end of the uncoiled wire adjacent and across themandrel rotates with the mandrel and the coiling head about the mandrelaxis to coil the wire around the mandrel and thereby form the coil. Thecoiling head is rotated a predetermined number of revolutions to producea definite number of turns in the coil body. Simultaneously with suchrotation the wire-feed-gripper slide is retracted longitudinally at arelatively slow rate in a direction away from the mandrel to provide adefinite turns per inch in the finished coil.

At the completion of the coil-winding operation the mandrel is furtherretracted at a faster rate to form the second straight uncoiled legportion on the filament, parallel to the longitudinal body of the coil.The mandrel is withdrawn from the coil and the second leg portion of thecoil is cut a required distance from the mandrel whereupon the woundcoil springs back a certain amount upon release from the coiling die.The first leg of the filament is then released by the wire-clampingfinger thereby permitting the finished filament to fall from thecoil-winding machine into a suitable container.

In order to compensate for the amount of spring-back in the coil (whichvaries from reel to reel of uncoiled Wire and depends upon theindividual characteristics of such wire) it has been known to use aconventional overwind device of the type shown in US. Patent No.2,439,893, issued April 20, 1948, to F. B. lden which device adds anadditional fraction turn to the body of the wound coil. This overwinddevice is utilized with a coil-winding machine which winds a coil havingthe straight uncoiled endleg portions extending transverse from the coilbody. Such prior-art overwind device has a cam and gear arrangement forrotating a carriage (which is slidable longitudinally of the mandrelaxis and which carries the wiresupply reel on its spindle) through apredetermined angle about the mandrel axis and at a uniform rate withrespect to the rotation of the mandrel and the coiling head to add orsubtract a fraction of a turn from the coil, thus providing compensationfor the spring-back of the coil on the mandrel when it is releasedtherefrom, and

back lash between the separate drives (due to the highrotational-inertia of the carriage) often causes inaccuracies in thedesired overwind and non-uniformity in the wound filaments. Further,considerable wear is encountered in the many moving parts of theconventional overwind device as disclosed in the above-mentioned patent,with re-' sultant maintenance problems and lost production time. Again,a machine of this type is subject to the further objection that theoverwind device is not readily accessible for maintenance and hencerequires complete dismantling of the device for the service of any ofits parts. In addition, the cost of this complex prior-art deviceclosely approximates a good proportion of the total cost of the entirecoil-winding machine. 7

A further disadvantage of this conventional overwind mechanism residesin the fact that it is rotated to its starting position during thereturn of the wire-feed-gripper slide to its starting position and thepresentation of the cut end of the uncoiled wire to the wire-grippingfinger preparatory for the winding of the next coil. Such rotation ofthe cut end of the uncoiled wire during the return movement too oftencauses such end to strike the open wire-gripping finger and makessecurement of such end therein impossible.

Another disadvantage of this prior art overwind de vice occurs withrespect to the desired uniform angularity of the straight uncoiled legportions of the coil with respect to the coil body. Even though suchoverwind device provides for spring-back in the coil body by theaddition or subtraction of a fractional turn to the coil body noprovision is made to prevent bowing of the second uncoiled leg portionwhen it is formed, since such second leg portion is under bending stressduring its formation due to the formation of a sharp radius betweentheend of the coil and the leg portion.

It is the general object of the present invention to avoid and overcomethe foregoing and other difficulties of and objections to prior artpractices by the provision of an improved overwind device having a lowrotational inertia which eliminates back-lash in the moving parts andprovides a consistent desired overwind with resultant uniformly woundfilament coils.

A specific object of the present invention is the provision of animproved overwind device which is readily accessible for any requiredmaintenance, is simple in construction, has relatively few moving parts,and is low in manufacturing cost.

A further object of the present invention is the provision of animproved overwind device which rotates to its starting position duringthe formation of the second straight uncoiled leg portion, therebyeliminating rotation of the cut end of the uncoiled wire during thepresentment of such cut end to the wire-gripping finger for securementof the lattertherein preparatory for the forming of the next coil.

Yet another object of this invention is the provision of an improvedoverwind device which utilizes its rotation to the starting position(during the formation of the second straight uncoiled leg portion) torotate such second uncoiled leg portion during its formation to preventbowing in such second uncoiled leg portion and to provide' a straightsecond leg portion and the same desired angularity with respect to thecoil body in such second leg portion as in the first leg portion.

The aforesaid objects of the present invention and other objects whichwill become apparent as the descriptracting a fraction of a turn to thecoil to insure the disposition of theleg portions of the coil in thesame plane and means for returning the coiling die to its startingposition during the formation of the second straight uucoiled legportion to provide a straight second leg portion. a t

For a better understanding of the present invention reference should-behad to the accompanying drawings, wherein like numerals of referenceindicate similar parts throughout the several views and wherein:

FIG. 1 is a fragmentary side-elevational view of the essential portionsof a coil-winding machine of the type shown in the above-mentioned US.Patent No. 2,179,-

296, which machine incorporates the improved overwind device of thepresent invention and shows such overwind device in the latched positionat the end of its return movement. I

FIG. 2 is a perspective view of the improved overwind device shown inFIG. 1.

FIG. 3 is a fragmentary side-elevational view of the cam means andassociated rack utilized. to drive the improved overwind device andshowing the rack in the unlatched position preparatory for the startingof a winding cycle.

FIG. 4 is a fragmentary side-elevationalview of the coiling die and aportion of the wire-feed-gripper slide, the parts being shown in theirpositions at the start of the winding cycle and corresponding in time tothe showing in FIG. 3.

FIG. 5 is a view similar to 'FIG. 3 and showing the rack at the end ofthe overwind operation.

' FIG. 6 is a view similar to FIG. .4 and showing the amount of theoverwind provided in the finished coil.

FIG. 7 is a view similar to FIGS. 3 and 5 but showing the latchedposition of the rack at the end of its return movement. FIG. 8 is a viewsimilar to FIGS. 4 and 6, taken alon the lines VIIIVIII of FIG. 1 in thedirection of the arrows and illustrating the return movement of thecoil: ing die preparatory for the presentment of the cut end of theuucoiled wire to the wire-clamping finger during movement of thewire-feed-gripper slide.

FIG. 9 is a vertical-sectional view taken along the; line IX-lXof FIG. 4in the direction of the arrows showing the coiling die, associated dieholder and pinion gear and a portion of the gear train used to drive thepinion gear.

FIG. 10 is a view similar to FIGS. 3, 5, 7 of an alternative embodimentof the overwind device of the' present invention where such device isutilized to sub tract a fraction of a turn from the body of the finishedcoil, showing the rack at the start of the winding opera 'Although theimproved overwind device of the present;

invention may be used generally with coil-winding machines of othertypes, 'such device is more particularly adapted'for use in conjunctionwith a coil-winding machine of the type shown in the above-mentionedU.S. Patent No. 2,179,296 and hence it has been so illustrated and willbe so described.

' With specific reference to the form of the present in ventionillustrated in the drawings, and referring particularly to FIG. 1, acoil-winding machine of the type shown in the above-mentionedUS. PatentNo. 2,179,296 is indicated generally by the reference numeral 10. Sincethe coil-winding machine 19, per se, forms no part of the presentinvention it is deemed sufllcient to only briefly describe its operationwith respect to the improved overcoiling head 32, a predetermined numberof turns in wind device of the present invention.

As shown in FIG. 1 a reel 12, which carries uucoiled wire 14, is mountedon a wire-feed-gripper slide 15 of the coil-winding machine -10; 'Thisslide is horizontally reciprocable by conventional means (not shovm) ona frame 17 of the coil-winding machine 10. To start the coil-windingoperation, an end of the uucoiled wire 14 from the reel 12 is fed byhand successively through a stationary jaw '16 and movable jaw 13 (whichhas been opened by conventional operating-means 9) and through alongitudinal Wire hole 20 (FIGS. 4, 6, 8, 9 and 11) in a coiling die 22(FIG. 2), with the end of the wire 14 projecting therefrom apredetermined amount. The jaws 16 and 18 are also mounted on the slide15 and the coiling die 22 is secured in a die holder 23 (FIG. 9) which 7holder is rotatable in the slide 15.

The coil-winding machine is then started. The end of the uucoiled Wire14 is moved by the slide 15 parallel to a retractable mandrel 26 whichhas been automatically inserted (by conventional means not shown) in alongitudinal mandrel hole 28 in the coiling die 22 and such end ispresented to an open wire-gripping finger 30 on the nose of a coilinghead 32 of the coil winding machine 10, which finger has been opened byoperation of the aforesaid conventional operating means 19. Thewiregr-ipping finger 30 is thereafter automatically closed about the endof the uucoiled wire 14 and the movable jaw 18 is automatically openedby the same convention-a1 operating end-leg-potrtion 34 (FIG. 12)preparatory for the coilingoperation.

The Wire-gripping finger 36 (holding the end of the uncoiled wire 14adjacent and across the mandrel 26) is rotated, along with the mandrel26 which telescopically engages the hole 28 in the die 22 as a bearingand the counterclockwise direction about the longitudinal axis of themandrel 26 (in the direction of the arrow shown in FIG. 1) byconventional means (not shown) to provide a predetermined number ofturns in the coil body 35 (FIG. 12

Simultaneously with this counterclockwise rotation of the coiling head32, the wirefeed gripper slide 15 is moved to the left, as viewed inFIG. 1, at a predetermined relatively slow rate by conventional means(not shown) to properly space the turns being'formed in the coil body35. During this movement of the slide 15 the die holder 23 and theceiling die 22 are rotated in counterclockwise direction, as viewed inFIG. 1, about the mandrel axis by the improved overwind device of thepresent invention thereby adding a fraction of a turn to the turns inthe coil body 35. This added fraction of a turn compensates for thespring-back in the coil body 35 when the coil is completed and releasedfrom the coil-winding machine 10 as hereinafter related.

Overwind Device In order to cause this counterclockwise rotation of thecoiling die 22 simultaneously with the rotation of the coiling head 32,a pinion gear 36 (FIGS. 2 and 9) 'afiixed to the die holder 23 androtatable therewith is connected by a gear train 38 to a rack 40 whichis vertically reciprocable in the wire-feed-gripper slide 15. This rack40 has a roller 42 biased by a compression spring 44 into engagementsuccessively with a stationary operating cam 46 and return cam 48. Theoperating cam 46 and the return cam. 48 are commonly pivoted at 50 on aplate 51 afiixed to the frame 17 of the coil-winding machine 10 and havetheir outer ends, as viewed in FIGS. 1 and 2, secured by suitable screwsin annular adjustment slots 52 and 54 respectively, provided in theplate 51.

The improved overwind device of the present invention utilizes theabovementioned movement of the wire-feedgripper slide 15 to the left(during the rotation of the coiling head 32) to drive the overwinddevice. This movement of the slide 15 causes the spring-biased roller42, carried by the slide 15, to ride upwardly on the stationaryoperating cant 46 (from the position shown in FIG. 3 to the positionshown in FIG. 5) thereby causing the rack 40 to move upwardly, as viewedin FIGS. 1 and 3. This upward movement of the rack 46 is transmitted bythe gear train 38 to the pinion 36 with resultant counterclockwiserotation of the latter, the die holder 23 and the coil die 22 (fromtheir position shown in FIG. 4 to the position shown in FIG. 6), therebycausing the attendant addition of a fraction of a turn to the coil body35. It will be understood thatsince the die holder 23 and coiling die 22are light in weight, their rotational inertia is low thus eliminatingback-lash in the moving parts and providing a consistent overwind insuccessive coils. It is obvious that the amount of overwind iscontrolled by the amount of vertical upward movement of the rack 40,which in turn is controlled by the angular displacement of theadjustable operating cam 46 with respect to the horizontal portion ofthe frame 17 (FIG. 2).

When the coiling head 32 and the coiling die 22 cease theircounterclockwise rotation, as viewed in FIGS. 1 and. 2, and the coilbody 35 is completed, the wire-feed gripper slide continues its movementto the left, as viewed in FIG. 1, at a relatively faster rate thanitsprevious rate of movement during the coiling operation to form thesecond straight uncoiled end-leg portion 56. It is obvious that theformation of the sharp radius between the end of the coil and the secondstraight uncoiled leg portion has stressed the leg portion 56 so that(contrary to the actual condition), if such leg portion 56 were free itwould assume the bowed dotted-line position shown in FIG. 12. Thiscontinued movement of the slide 15 to the left causes the roller 42 tomove from the position shown in FIG. 5 along the surface of the re-'turn cam 48 to the position shown in FIG. 7 with resultant lowering ofthe rack 40 to the position shown in FIGS. 1 and 2 and attendantclockwise retracting rotation of the coiling die 22 to its startingposition shown in FIG. 8. Duringthis retracting rotation of the coilingdie 22 the second straight uncoiled end-leg portion 56 is also rotatedin like direction (at a faster rate than the natural uncoiling rate ofthe coil body 35 which is still on the mandrel 26) thus preventingbowing of the straight second leg portion 56 during its formation andproviding a straight portion 56. This retractive rotation of the coilingdie 22 also permits the coil body 35 to spring back while still on themandrel 26, to align the second leg portion 56 along a line through thefirst end-leg portion 34.

When the roller 42 arrives at this position shown in FIGS. 1, 2 and 7, alatch 58 pivoted :at 60 on a bracket 62 afiixed to the wire-feed-gripperslide 15 slides into a notch 66 (FIGS. 1, 2, 3, 5, 7 and 11) provided inthe left-hand face of the rack 49 thereby locking the rack 41 and thecoiling die 22 in the position shown in FIGS. 1 and 2. The latch 58 isbiased by a tension spring 64 (FIGS. 1 and 2) into engagement with theleft-hand face, as viewed in FIG. 3, of the rack 40. Such spring 64extends from a lug 65 projecting from the slide 15 to a rod 67 carriedby the latch 58.

The mandrel 26 is then withdrawn from the mandrel hole 28 in the coilingdie 22 and the second straight uncoiled end-leg portion 56 is then cutby conventional cutting means (indicated generally in FIG. 1 by thereference numeral 69) a predetermined distance from the coiling die 22,without any appreciable further spring back of the coil body 35. Thefirst straight uncoiled leg portion 34 is released from thewire-clamping finger 30 by operation of the operating means 19 therebypermitting the finished coil to drop from the coil-winding machine 10into a container (not shown). Operation of the operating means 19 alsocauses the movable jaw 18 to close 6 preparatory for the presentment ofthe cut end of the uncoiled wire 14 to the now open wire-clamping finger30 during movement of the Wire-feed-gripper slide 15 to the right, asviewed in FIG. 1.

It ils obvious from a consideration of FIGS. 1, 3 and 4 that (duringsuch movement of the wire-feed-gripper slide 15 to the right) the roller42, locked in the position in FIG. 3, moves horizontally in thedirection of the horizontal arrow shown in FIG. 3 from the dotted-lineposition, shown in such figure, to the solid-line position showntherein. As the roller 42 approaches such solid-line position shown inFIG. 3, the rod 67 on such latch58 engages the head of an adjustablestop: 68 mounted in a bracket 70 affixed to the plate 51, therebyrotating the latch 58 in a clockwise direction (FIG. 3) about its pivot60 against the action of the tension spring 64, and moving such latch 58out of the notch 66 preparatory for the next coil-winding operation.

' It will be recognized by those skilled in the art that the objects ofthe present invention have been achieved by providing an improvedoverwind device having a low rotational inertia thus eliminating backlash in the moving parts and providing a consistent desired overwindwith resultant uniformly wound filament coils. Such improved overwinddevice is readily accessible for any required maintenance, is simple inconstruction, has relatively few moving parts and is low in cost. Thedevice eliminates rotation of the cut end of the wire-gripping-fingerfor securement of the latter therein preparatory for the nextcoilwinding operation. In addition, the improved overwind device usesits retracting rotation to the starting position (during the formationof the second straight uncoiled leg portion) to rotate such secondstraight uncoiled endleg portion in a direction opposite to the coilingrotation thereby releasing any bending stresses therein and pro vidingthe same desired angularity in both leg portions.

As an alternative embodiment to the preferred embodiment shown in FIGS.18, it is possible to subtract a fraction of a turn from the coil body35. In such alternative embodiment shown in (FIGS. 10 and 11 theoperating cam 46 and the return cam 48 may be positioned as shown inFIG. 10.

Then, during the above-described coil-winding operation the rack 40 islowered, as viewed in FIG. 10, and the pinion 36, coiling die holder 23and coiling die 22 are rotated in clockwise direction about thelongitudinal mandrel axis, as viewed in FIG. 11 to subtract a'fractionof a turn from the total number of turns being formed in the coil body35' by the coiling head 32.

While in accordance with the patent statutes one best known embodimentof the present invention has been i1- lnstrated and described in detail,it is to be particularly understood'that the invention is not limitedthereto or thereby.

I claim:

1. An overwind device for a coil-winding machine having a coiling headrotatable to form a coil provided with a coil body, a first uncoiledend-leg portion and a second uncoiled end-log portion, said. overwinddevice comprising a coiling die, means connected to the coiling die forrotating it through a predetermined angle in one direction during therotation of the coiling head to form the coil body thereby varying by afraction of a turn the total number of turns in the coil body to insurethe disposition of the uncoiled end-leg portions of the coil in the sameplane, and means also connected to the coiling die for returning thecoiling die to its starting position after the formation of the coilbody, for rotating the second uncoiled end-leg portion and the coil bodyin the other direction during the formation of the second uncoiledend-leg portion thus providing a straight second uncoiled end-legportion and for allowing the coil body to spring back thus aligning thefirst and second uncoiled end-leg portions in the same plane.

7 2. For a coil-winding machine having a wire-feed-gripper slide and acoiling head rotatable to form a coil provided with a coil body, a firstuncoiled end-leg portion and a second uncoiled end-l eg portion, anoverwind device comprising a coiling die, means connected to the coilingdie for rotating the coiling diethrough a predetermined angle in onedirection during the rotation of the coiling head to form the coil bodyand operable by movement of the wire-feed-gripper slide during thespacing of the turns in the coil body thereby varying by a fraction of aturn the total number of turns in the coil body to insure thedisposition of the uncoiled end-leg portions of the coil in the sameplane and means also connected to the coiling die for returning thecoiling die to its starting position aiter the formation of the coilbody and operable by movement of the wire-feed-gripper slide to rotatethe second end-leg portion and the coil body in the other directionduring the formation of the second uncoiled end-leg portion thusproviding a straight, second uncoiled end-leg portion and to allow thecoil body to spring back thus aligning the first and second uncoiledend-leg portions in the same plane.

3. For a coil-winding machine having a wire-feed-gripper slide and acoiling head rotatable to form a coil provided with a coil body, a firstuncoiled end-leg portion and a second uncoiled end-leg portion, anoverwind device comprising a. coiling die, rotating means connected tothe coiling die, a first means operatively associated with the rotatingmeans for causing rotation of the coiling die through a predeterminedangle in one direction during the rotation of the coiling head to formthe coil body and operable by movement of the :wire-feed-gripper slideduring the spacing of the turns in the coil body thereby varying by afraction of a turn the total number of'turns in the coil body to insurethe disposition of the uncoiled endleg portions of the coil in the sameplane and a second means also operatively associated with the rotatingmeans for causing the return of the coiling die to its starting positionafter the formation of the coil body and operable by movement of thewire-feed-gripper slide to rotate the second uncoiled end-leg portionand the coil'body in the other direction during the formation of thesecond un-- coiled end-leg portion thus providing a straight seconduncoiled end-leg portion and to allow the coil body to spring back thusaligning the first and second uncoiled end-leg portions in the sameplane. I p

4. For a coil-winding machine having a wire-feedgripper slide and acoiling head rotatable to wind an elongated article into a coibprovidedwith a coil body, a first uncoiled end-leg portion and a second uncoiledend-leg portion, an overwind device comprising a coiling die, rotatingmeans connected to the coiling die, a first means operatively associatedwith the rotating means for causing rotation of the coiling die througha predetermined angle in onedirection during the rotation of the coilinghead to form the coil body and operable" by movement of thewire-feed-gripper slide during the spacing of the turns in the ooil bodythereby varying by a fraction of a turn the total number of turns in thecoil body to insure the disposition of the uncoiled endleg portions ofthe coil in the "same plane, a second means also operatively associatedwith the rotating means for causing the return of thecoiling' die to itsstarting position after the formation of the coil body and operable bymovement of the Wire-feed-gripper slide to rotate the second uncoiledend-leg portion and the coil body'in the other direction during theformation of the second uncoiled end-leg portion thus providing astraight second uncoiled end-leg portion and to allow the coil body tospring back thus aligning the first and second uncoiled end-leg portionsin the same plane and latching means on the wire-feed-gripper slideoperable to lock the rotating means in its starting position to preventrotation of the coiling die during presentment of an end of theelongated article by the Wire-feed-gripper slide to the coiling head forsecurement therein. 7

5. For a coil-winding machine having a Wire-feedgripper slide and aceiling head rotatable to Wind an elongated article into a coil providedwith a coil body, a first uncoiled end-leg portion and a second uncoiledend-leg portion, an overwind device comprising a coiling die, a rackreciprocable in the Wire-feed-gripper slide, gear means connected to thecoiling die and to the rack for translating the reciprocating movementof the rack into rotational movement of the coiling die, a first camciated with the rack for causing the return of the coiling die to itsstarting position after the formation of the coil body and operable bymovement of the wire-feed-gripper slide to rotate the second uncoiledend-leg portion and the coil body in the other direction during theformation of the second uncoiled end-leg portion, thus providing astraight second uncoiled end-leg portion and to allow the coil body tospring back thus aligning the first and second uncoiled end-leg portionsin the sam plane, latching means on the wire-feed-gripper slide operableto lock the rack in its starting position to prevent rotation of thecoiling die during presentment of an end of the elongated article by thewire-feed-gripper slide to the coiling head for secureme'nt therein, andstop means engageable by said latching means near the end of thepresenting movement of the wire-feed-gripper slide to release such rackpreparatory for the next coiling operation.

References Cited in the file of this patent UNITED STATES PATENTS2,197,296 Iden Nov. 7, 1939 2,439,893 Iden Apr. 20, 1948 2,801,670 WolfAug. 6, 1957

